Hi Just a quick follow-up video to my previous Led ceiling light installation. Click here if you haven't seen it now. I Was reminded that I actually forgot to do something which I was going to include in the video a test and that's to see if turning on the lights actually caused any in a common mode noise issues that can be picked up on. you know when I'm measuring stuff here on the bench and don't? Yep, forgot to try it.

So let's give it a go. compare the new lights to the old lights and see what the difference is. Now what I've got here is my scope set to 5 millivolts per division. I've just got a B and C to Banana Plug.

I'm just you know. AC Coupling Measuring the output noise of this power supply like just there is something really simple. Okay, and we can see that there's something there. Oh, look at that.

that's you can see that that's my hand. There's noise folks anyway, and that's picking up the switching noise from the screen inside the scope which is coupling in. Anyway, let's not go there. I Just noticed that now I've done a whole separate video on common mode noise and actually trying to detect it in and things like that.

So click here if you haven't seen that one as well. So I won't go into explaining called mode noise and all the different types of noise and pickup and everything else. that's too confusing I just want to see if these new lights actually do anything at all. Ok, so I've actually got two switched on at the moment and so let's have a look at my screen here.

Okay, so here's the noise. with just two of the nine of my new LED lights turned on and you'll notice that there's a little spike there which I'm actually triggering off I won't touch the screen anymore. That's a bit bad and we've got something happening in there. But let's go and turn the lights off and see if that goes away.

I've got all my lights off in the lab and nope, so those lights weren't causing that at all. It's got absolutely nothing to do with it. Okay, so I've got two of my lights on. Now it now.

I'll go up to my next level and I'll turn on I think three more and there we go. Still bugger-all and let's switch on the rest. Here we go and OH turn on. I've now got nine lights on I've got all my lights on here and as you can see, sorry about a little bit of glare on the screen there as you can see the new lights basically cause no noise whatsoever.

Okay, I'm back to two lights here. two new lights. Now let's plug in three of my old lights down beside me and see what we did. That is an absolute shocker.

The old ones were awful. Look at that haha and I disconnect and it goes away. reconnect. Bingo.

There it is. Look and something's seriously wrong with the switching converters. The crap one: Hungarian switching inverters in I Want to do with my old lights there. They were awful.

No actually. I've found a similar problem with these lights before in that when I would switch them all on I to get extra noise. So I've actually narrowed it down to one particular switch in plug pack here and let me show you. And here we go.

So we're getting all that shocking noise. but I'll disconnect the culprit here we go. Gone. ski, look at that.

So now we're back to where we were before. So it was one particular plug pack. it actually wasn't all of the existing lights. you know, actually doing that.

They will do it though because the existing lights were capable of our pulse width modulation ie. dimming I could actually I had a remote control for the previous ones that I could actually dim and if you did them, yeah, you got some pretty horrible noise all around the place. but I always ran on full brightness so they weren't actually moderate. You know, pulse width modulated the lights.

it was just, you know, constant current. like these. these new ones are just continuous constant current. So really, these new lights? no problems whatsoever.

Dodgy one. Hungarian Plug back on the old one. now. it's actually powering that panel over there before and now I've actually switched it over this one.

Try and diagnose the problem. Now this old one actually comes with two separate things. We've got the mains plug pack which just gives a standard 24 volt DC output. and then we've got the actual constant current driver itself.

and I've narrowed it down to this plug pack. So I've taken this good panel that wasn't giving any switching noise before using its constant current regulator and plug it into this dodgy power adaptor. There's one on low one and that came from literally one hung low like there is no brand on that whatsoever. It's just made in China Thank you very much.

this was the culprit. So this is actually this plug pack is connected to the mains here, so if there's no load on it, there's no problem whatsoever. There's no switching noise. But the second that we actually load this sucker down, woohoo, There we go.

There's all that horrible switching noise. What a piece of that plug pack is. So there you go, these new lights. No problems whatsoever in terms of switching.

Got a top quality plug pack there as opposed to this piece of and there's only one place for this. Catch you next time you.